The present invention relates generally to spindle finishing machines and more specifically, to workpiece holders for use in supporting workpieces while they are subjected to a finishing operation within a mass of rotating finishing media. In particular, the present invention relates to a new and improved workpiece holding apparatus wherein in workpieces are subjected to a compound rotational movement during the finishing operation so that the workpieces are uniformly finished in a minimum amount of time. Such movement is accomplished through the provision of a novel turret head having a plurality of radially disposed workpiece holders, each of which are intended to rotate about a common upwardly inclined rotational axis, and simultaneously, each of the workpiece holders is rotated about its respective longitudinal axis through the provision of cooperating gear elements located within the turret head. The workpiece holders are provided with workpiece retaining means, such as spring biased collets, that are adapted to be selectively actuated between a first condition wherein the workpieces are positively secured to the outer ends of the holders, and a second condition wherein the workpieces may be removed and replaced with new workpieces to be finished during a subsequent rotational cycle of the turret head. Actuation of the workpiece holders is achieved through the provision of a novel camming arrangement which cooperates with the draw rods and collets of the respective workpiece holders, with the particular cam means being selectively located such that the workpiece holders are actuated to their respective "release" condition as the workpieces carried thereon are rotated out of the mass of finishing media. Alternate embodiments of the present invention include workpiece retaining heads that may be clampingly engaged directly with the workpieces, or instead, with retaining pins which temporarily support the workpieces on the workpiece holders during a finishing operation. Yet another alternative arrangement utilizes a vacuum source for releasably securing the workpieces upon the workpiece holders.
It is accordingly a general object of the present invention to provide a new and improved workpiece holding apparatus for use with spindle finishing machines and the like.
It is a more particular object of the present invention to provide a new and improved workpiece holding apparatus which includes means for applying a positive driving force to the workpieces as they are being finished so as to assure uniformity of the finishing operation.
It is still a further object of the present invention to provide a workpiece holding apparatus, as above described, wherein the workpieces are positively retained in place by a unique spring set collet arrangement.
It is a further object of the present invention to provide a workpiece holding apparatus, as above described, wherein the workpieces are subjected to a compound rotational movement, and wherein the workpiece holders may be selectively actuated to release the workpieces by means of a cam arrangement disposed interiorly of the workpiece turret head.
It is still a further object of the present invention to provide a new and improved workpiece holding apparatus that will find universality of application with various types of spindle finishing machines and which is of a relatively simple design, durable construction and will therefore have a long and effective operational life.
Other objects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.